The invention relates to an instant thread dyeing method for sewing machines and, more particularly, to a method for instantly dyeing a sewing machine thread with different colors as desired while the thread is used with a sewing machine in stitching operation.
In the prior art it has been necessary to prepare many threads of different colors as required to be used for a stitching operation, especially for making pattern stitches and embroidery stitches with a sewing machine, and to selectively use these threads of different colors in dependence upon the kind of pattern stitches or embroidery stitches. If the sewing machine operator desires to provide a complicated embroidery stitches requiring many different colors according to such conventional manner, the operator is required to interrupt the stitching operation so as to change the sewing thread each time a different colored thread is to be used. Such a thread changing operation is considerably troublesome and time-consuming.
It is therefore desired to provide a method for dyeing a white or colorless thread with any given color without interrupting the stitching operation. However, many difficulties arise in providing such a method which will have to satisfy all of the following requirements;
(a) the thread dyeing treatment must be carried out with a sufficient speed corresponding to a thread consumption speed (i.e., about 1-15 cm/sec.) during the stitching operation;
(b) the thread dyeing treatment will not change the characteristics such as the slidability and flexibility of the thread;
(c) the dyeing effect will be perfect;
(d) the dyeing treatment may be adapted to any kind of threads; and
(e) the thread dyeing device must be simple and compact in structure and easy to use.